To be clear, this was in no way an attack on your personal rock, just used rock in general, and accumulating too much of it "just because" :)

Lol no worries and I agree with the clean is better comment if anything was building up crud or getting dirty looking it would be gone I just would hate to see good rock be wasted :biggrin:

Lol I only put those beautiful pieces in the sump for now till I have more time this weekend to rearrange my rock work. Also gives time the those amazing pieces u gave me to acclimate to my lights. They look awesome under my LEDs!!
Are acro crabs bad? I did find a lot of baby snail with white and purple strips

A wrasse should eat up those snails for you :biggrin:

The little snails are reef safe btw if you like them.

I think there's value in both approaches, replacing vs. keeping. The condition of the rock and how it will impact a system over time can be affected by so many different things over the course of a few years, most of which you'll never be able to really test for in any significant way.

As a general rule I look at rock that's in systems that have never had algae problems (or haven't had them in many months/years), and have always been actively maintained to have very low dissolved nutrients as being less likely to be a source of problems. Rock that's spent time in nutrient laden waters and/or supporting lush macro algae growth are more likely to cause you issues and likely require cooking, maybe even following bleaching or a treatment with muriatic acid. If it's from a sump where there's no light, I'd look at the condition of the rocks in the tank above to try and get an idea of what sort of nutrient regime those rocks have been exposed to over time.

However, for me personally, if it was just to increase real estate for corals in my own tank and my tank was already up, running, and stable, I would probably just go with dead marco or fiji rock that had been cooked for a few weeks. Not sure why you'd need live rock from another system when the dead stuff will eventually end up as live after a few months in an already matured system. The risks of adding rock from another system unless there's a specific reason to do it outweigh any potential benefit compared to using dead rock IMO, regardless of how pristine the original system was.

If this is a new set up and this is 100% of your rock, then it's a totally different story. Getting rock from someone else's sump, assuming that sump and system in general are well maintained is probably a whole lots safer than getting rock from a fish store holding tank. You'll have an instantly cycled tank with cured rock, and you'll know the history of the rock and what it's potential issues might be. Rock from holding tanks are a total crap shoot, and I shudder to think what a test for nitrate and phosphate in one of those bins would return.

I got rocks from him from convienience cuz I got a bunch of frags from him. Anyways, I thought u can't put dry rock into an established tank because it will cause a "new tank syndrome"

How do you define 'new tank syndrome'?

Are you talking about a spike in ammonia? That's only possible if the rocks you're putting in have lots of dead stuff on them. Marco rocks have very little on them that could cause an ammonia spike, but some of the dry fiji rock that I've seen looks like it might.

That can be mitigated by letting them sit in salt water for a week or so, but if it was a small amount of rock relative to the system, and the system was mature, I'm not sure I'd even bother doing that. A mature system has many different pathways for dealing with ammonia, and it's capacity is pretty elastic. It's why you don't see ammonia spikes every time you add a new fish to a mature system.

Anyway I'm pretty relaxed about most of this stuff, so other people might disagree, and it is technically possible for other things your don't want to leach out of the rock like phosphates, or to cause a spike in nitrates, so it's never bad advice to say let it cure in a bucket of salt water with a power head for a week or two, but that's about as far as I'd go. If you did that, you're pretty much guaranteed for it's measurable effect on your system, other than increasing real estate, to be nil.

ETA: the only other effect of adding dry dead rock to a system that I've read about is some sort of temporary impact on alkalinity. Not sure of the chemistry behind it or if it would be a big deal if it actually happened, but that too could be mitigated by soaking the rocks in salt water for a week or two first.